Photovoltaic element, producing method therefor, and solar cell modules

Abstract

A photoelectric conversion layer 13 , a transparent electrode layer 14 , an insulating layer 15 , and a back electrode layer 16 are successively formed in this order on a conductive substrate 11 having a through-hole 17 formed therein, and the transparent electrode layer 14 and the back electrode layer 16 are electrically communicated with each other through the through-hole 17 so as to provide a photovoltaic element in which no grid is employed and improve the productivity and the production yield.

What is claimed is:  
     
       1. A method of producing a photovoltaic element comprising a conductive substrate having a through-hole, a transparent electrode layer and a photoelectric conversion layer in this order from a light-receiving face side of the conductive substrate on a major surface of the light-receiving face side of the conductive substrate, and an insulating layer and a back electrode layer in this order from the light-receiving face side on a major surface of a non-light-receiving face side of the conductive substrate; the method comprising: 
       a first step of successively forming the photoelectric conversion layer and the transparent electrode layer on the major surface of the light-receiving face side of the conductive substrate and on an inner wall face of the through-hole; and  
       a second step of successively forming the insulating layer and the back electrode layer on the major surface of the non-light-receiving face side of the conductive substrate and on the inner wall face of the through-hole.  
     
     
       2. The method according to  claim 1 , further comprising a step of producing the conductive substrate having the through-hole by perforating a through-hole in a conductive substrate, where burr to be generated in through-hole formation is mainly generated on the non-light-receiving face side of the conductive substrate. 
     
     
       3. The method according to  claim 2 , wherein the step of forming the through-hole is a punching step using a punch and a die which is conducted by punching the conductive substrate from the light-receiving face side while arranging the punch on the light-receiving face side of the conductive substrate and the die on the non-light-receiving face side. 
     
     
       4. The method according to  claim 2 , wherein the step of forming the through-hole is a laser processing step which is conducted by irradiation of laser beam from the light-receiving face side of the conductive substrate. 
     
     
       5. The method according to  claim 2 , further comprising a step of removing burr generated in the through-hole formation between the step of forming the through-hole and the first step. 
     
     
       6. The method according to  claim 5 , wherein the step of removing the burr is carried out by electrolytic polishing. 
     
     
       7. The method according to  claim 1 , wherein formation of the photoelectric conversion layer in the first step is carried out by a chemical vapor deposition method. 
     
     
       8. The method according to  claim 1 , wherein a step of selectively removing the transparent electrode layer is inserted between the first step and the second step. 
     
     
       9. The method according to  claim 1 , wherein a short-circuit point removal step of restoring short-circuit fault is inserted between the first step and the second step. 
     
     
       10. The method according to  claim 9 , wherein the short-circuit point removal step is carried out by causing electrolytic reaction by applying voltage between the conductive substrate and a counter electrode in an electrolytic solution. 
     
     
       11. The method according to  claim 1 , wherein formation of the insulating layer in the second step is carried out by a chemical vapor deposition method. 
     
     
       12. A photovoltaic element comprising: 
       a conductive substrate having a through-hole;  
       a transparent electrode layer and a photoelectric conversion layer in this order from a light-receiving face side of the conductive substrate on a major surface of the light-receiving face side of the conductive substrate; and  
       a rectification layer and a back electrode layer in this order from the light-receiving face side on a major surface of a non-light-receiving face side of the conductive substrate,  
       wherein the photoelectric conversion layer and the transparent electrode layer are formed continuously from the major surface of the light-receiving face side to at least a part of an inner wall face of the through-hole; the rectification layer and the back electrode layer are formed continuously from the major surface of the non-light-receiving face side to at least a part of the inner wall face of the through-hole; the transparent electrode layer and the back electrode layer are electrically communicated with each other through the through-hole; and a rectification characteristic of the rectification layer is in an inverse direction to a voltage of a photoelectric motive force of the photoelectric conversion layer.  
     
     
       13. The photovoltaic element according to  claim 12 , wherein the photoelectric conversion layer is continuously formed from the major surface of the light-receiving face side to at least a part of the major surface of the non-light-receiving face side through the through-hole. 
     
     
       14. The photovoltaic element according to  claim 12 , wherein the conductive substrate is so arranged as to leave burr or burr residues generated in the formation of the through-hole of the conductive substrate mainly on the non-light-receiving face side. 
     
     
       15. The photovoltaic element according to  claim 12 , wherein a shape of the through-hole is approximately circular as viewed from the major surface of the light-receiving face side and as viewed from the major surface of the non-light-receiving face side and satisfies that T/D is 1 or lower, wherein T denotes a thickness of the conductive substrate and D denotes a hole diameter of the through-hole. 
     
     
       16. The photovoltaic element according to  claim 12 , wherein a shape of the through-hole is approximately rectangular as viewed from the major surface of the light-receiving face side and as viewed from the major surface of the non-light-receiving face side and satisfies that T/L is 1 or lower, wherein T denotes a thickness of the conductive substrate and L denotes a width of the through-hole in a shorter side thereof. 
     
     
       17. The photovoltaic element according to  claim 12 , further comprising a back reflection layer between the conductive substrate and the photoelectric conversion layer, wherein the back reflection layer is formed continuously from the major surface of the light-receiving face side to at least a part of the inner wall face of the through-hole. 
     
     
       18. The photovoltaic element according to  claim 12 , further comprising a back reflection layer between the conductive substrate and the photoelectric conversion layer, wherein the back reflection layer is formed continuously from the major surface of the light-receiving face side to at least a part of the major surface of the non-light-receiving face side through the through-hole. 
     
     
       19. The photovoltaic element according to  claim 17 , wherein the back reflection layer is composed of a metal layer and a semiconductor layer. 
     
     
       20. The photovoltaic element according to  claim 12 , wherein the rectification layer has any one selected from the group consisting of a PN junction, a PIN junction, a hetero junction and a Schottky barrier. 
     
     
       21. The photovoltaic element according to  claim 12 , wherein the rectification layer is composed of amorphous, crystalline, or a mixture of amorphous and crystalline material. 
     
     
       22. The photovoltaic element according to  claim 12 , wherein the rectification layer is composed of any one selected from the group consisting of an amorphous silicon-based semiconductor, a microcrystalline silicon-based semiconductor, a polycrystalline silicon-based semiconductor, and a polycrystalline compound-based semiconductor. 
     
     
       23. The photovoltaic element according to  claim 12 , wherein the photoelectric conversion layer has any one selected from the group consisting of a PN junction, a PIN junction, a hetero junction and a Schottky barrier. 
     
     
       24. The photovoltaic element according to  claim 12 , wherein the photoelectric conversion layer is composed of amorphous, crystalline, or a mixture of amorphous and crystalline material. 
     
     
       25. The photovoltaic element according to  claim 12 , wherein the photoelectric conversion layer is composed of any one selected from the group consisting of an amorphous silicon-based semiconductor, a microcrystalline silicon-based semiconductor, a polycrystalline silicon-based semiconductor, and a polycrystalline compound-based semiconductor. 
     
     
       26. The photovoltaic element according to  claim 12 , wherein the conductive substrate is made of a flexible metal sheet. 
     
     
       27. A solar cell module comprising a photovoltaic element as claimed in  claim 12  and a sealing material, wherein at least a part of the photovoltaic element is covered with the sealing material. 
     
     
       28. A method of producing a photovoltaic element comprising a conductive substrate having a through-hole, a transparent electrode layer and a photoelectric conversion layer in this order from a light-receiving face side of the conductive substrate on a major surface of the light-receiving face side of the conductive substrate, and a rectification layer and a back electrode layer in this order from the light-receiving face side on a major surface of a non-light-receiving face side of the conductive substrate; the method comprising: 
       a first step of successively forming the photoelectric conversion layer and the transparent electrode layer on the major surface of the light-receiving face side of the conductive substrate and on an inner wall face of the through-hole; and  
       a second step of successively forming the rectification layer and the back electrode layer on a major surface of a non-light-receiving face side of the conductive substrate and on the inner wall face of the through-hole,  
       wherein a rectification characteristic of the rectification layer is in an inverse direction to a voltage of a photoelectric motive force of the photoelectric conversion layer.  
     
     
       29. The method according to  claim 28 , comprising a step of producing the conductive substrate having the through-hole by perforating a through-hole in a conductive substrate, wherein the through-hole is formed so that burr generated in the through-hole formation is mainly generated on the non-light-receiving face side of the conductive substrate. 
     
     
       30. The method according to  claim 29 , wherein the step of forming the through-hole is a punching step using a punch and a die which is conducted by punching the conductive substrate from the light-receiving face side while arranging the punch on the light-receiving face side of the conductive substrate and the die an the non-light-receiving face side. 
     
     
       31. The method according to  claim 29 , wherein the step of forming the through-hole is a laser processing step which is conducted by irradiation of laser beam from the light-receiving face side of the conductive substrate. 
     
     
       32. The method according to  claim 29 , further comprising a step of removing the burr generated in the through-hole formation between the step of forming the through-hole and the first step. 
     
     
       33. The method according to  claim 32 , wherein the step of removing the burr is carried out by electrolytic polishing. 
     
     
       34. The method according to  claim 28 , wherein the formation of the photoelectric conversion layer in the first step is carried out by a chemical vapor deposition method. 
     
     
       35. The method according to  claim 28 , further comprising a step of selectively removing the transparent electrode layer between the first step and the second step. 
     
     
       36. The method according to  claim 28 , further comprising a short-circuit point removal step of restoring short-circuit fault between the first step and the second step. 
     
     
       37. The method according to  claim 35 , wherein the short-circuit point removal step is carried out by causing electrolytic reaction by applying a voltage between the conductive substrate and a counter electrode in an electrolytic solution. 
     
     
       38. The method according to  claim 28 , wherein formation of the rectification layer in the second step is carried out by a chemical vapor deposition method.